This invention relates to a vehicle wheel and especially to a bicycle wheel having a rim section, a plurality of spoke sections and a hub section.
In recent years, participation in competitive cycling has increased dramatically and has created a demand for greater performance characteristics from cycling equipment. It is generally acknowledged that reduced aerodynamic drag, lower weight, increased rider comfort, low maintenance and reduced cost are goals to consider when attempting to enhance the performance of bicycle equipment.
Conventional bicycle wheels are typically constructed using twenty eight or more individual wire spokes. Each of these spokes must continually break the wind as the wheel rotates, creating aerodynamic drag. An attempt to overcome some of this aerodynamic drag has been to construct the bicycle wheel as a solid disc. Although these disc wheels reduce the aerodynamic drag, rider stability and safety are significantly compromised. If prevailing wind patterns have any component perpendicular to the riders direction of travel, as is most often the case, the disc wheel acts as a sail resulting in a potentially dangerous instability problem. More recently, several manufacturers have introduced one-piece spoked wheels constructed from fiber reinforced plastic. These wheels attempt to reduce aerodynamic drag by reducing the number of individual spokes to three or five. However, in an effort to maintain lateral rigidity, these wheels utilize additional material in construction and weigh significantly more than a conventional wheel of comparable size. Additionally, the manufacturing processes required to produce these plastic spoke wheels are quite complex. Fabrication involves careful wrapping of fiber reinforcement cloth around a foam armature or plastic bladder, placing this assembly within a mold, together with uncured resin, and applying heat and pressure to the mold to cure the resin. This process is very labor intensive and requires highly skilled production personnel. Also, the disc type wheels and the plastic spoke wheels have been described as lacking the shock absorption and resiliency of conventional wheels, resulting in a more uncomfortable ride. These disc type wheels and plastic spoke wheels act to support a load on the axle through compression of the spoke or disc sector between the hub and the ground resulting in excessive rigidity. Conventional wheels support this load through tension of the spokes above the hub. It is this tension loading which gives the conventional wheel its resilient feel.
Accordingly, it is an object and advantage of the present invention to provide a bicycle wheel that can be manufactured at a reasonable cost through a configuration which lends itself to simple manufacturing processes, fewer component parts and minimal raw material.
It is a further object and advantage of the present invention to provide a bicycle wheel that has very low aerodynamic drag by limiting the number of individual spokes and minimizing the spoke frontal area in the direction of rotation.
It is a still further object and advantage of the present invention to provide a bicycle wheel that is stable and easy to control in all normal wind conditions.
A still further object and advantage of the present invention is to provide a bicycle wheel that is of particularly light weight by utilizing lightweight, high strength materials and by reducing the volume of material required to produce a structurally sound product.
An additional object and advantage of the present invention is to provide a bicycle wheel that does not require periodic rim alignment adjustments.
A further object and advantage of the present invention is to provide a bicycle wheel which affords the cyclist a comfortable resilient ride.
Further objects and advantages will become apparent from consideration of the ensuing description and drawings.